News

Looming Threat of Water Scarcity

26 March 2013

ANALYSIS - Last Friday - 22 March - was World Water Day. It is held each year as a means of focusing attention on the importance of freshwater and advocating for the sustainable management of freshwater resources, writes Chris Harris.

An international day to celebrate freshwater was recommended at the 1992 United Nations Conference on Environment and Development (UNCED). The United Nations General Assembly responded by designating 22 March 1993 as the first World Water Day.

Each year, World Water Day highlights a specific aspect of freshwater.

This year, which is the International Year of Water Cooperation, World Water Day was also dedicated to the theme of cooperation around water and is coordinated by UNESCO in collaboration with UNECE and UNDESA on behalf of UN-Water.

At the same time as events were taking place around the world to mark the occasion and to highlight the importance and ned for water sustainability, the Worldwatch Institute released a study examining global water use and steps to address water scarcity.

Globally 1.2 billion people —almost a fifth of the world — live in areas of physical water scarcity, while another 1.6 billion face what can be called economic water shortage.

The situation is only expected to get worse as population growth, climate change, investment and management shortfalls, and inefficient use of existing resources restrict the amount of water available to people, according to Worldwatch Institute’s Vital Signs Online service.

It is estimated that by 2025, 1.8 billion people will live in countries or regions with absolute water scarcity, with almost half of the world living in conditions of water stress.

Water scarcity comes in several forms.

Physical scarcity occurs when there is not enough water to meet demand and its symptoms include severe environmental degradation, declining ground water and unequal water distribution.

Economic water scarcity occurs when there is a lack of investment and proper management to meet the demand of people who do not have the financial means to use existing water sources. The symptoms in this case normally include poor infrastructure.

Large parts of Africa suffer from economic water scarcity.

A region is said to face water scarcity when supplies fall below 1,000 cubic meters per person, and absolute water scarcity is when supplies drop below 500 cubic meters a year.

About 66 per cent of Africa is arid or semiarid, and more than 300 million people in sub-Saharan Africa currently live on less than 1,000 cubic meters of water resources per person.

According to UN Water, each person in North America and Europe (excluding former Soviet Union countries) consumes at least three cubic metres per day of virtual water in imported food, compared with 1.4 cubic meters per day in Asia and 1.1 cubic meters per day in Africa.

World population is predicted to grow from 7 billion to 9.1 billion by 2050, putting a strain on water resources to meet increased food, energy, and industrial demands.

But there are many other pressures, including increased urbanisation and overconsumption, lack of proper management, and the looming threat of climate change.

According to the United Nations Food and Agriculture Organization and UN Water, global water use has been growing at more than twice the rate of population increase in the last century.

At the global level, 70 per cent of water withdrawals are for the agricultural sector, 11 per cent are to meet municipal demands, and 19 per cent are for industrial needs. These numbers, however, are distorted by the few countries that have very high water withdrawals, such as China, India and the United States.

Agricultural water withdrawal accounts for 44 per cent of total water withdrawal among members of the Organisation for Economic Co-operation and Development (OECD), but this rises to more than 60 per cent within the eight OECD countries that rely heavily on irrigated agriculture.

In the four transitional economies of Brazil, Russia, India, and China, agriculture accounts for 74 per cent of water withdrawals, but this ranges from 20 per cent in Russia to 87 per cent in India.

The shortages and water problems in India could also be exacerbated by the retreat of glaciers in the Himalayas which is having a detrimental effect on monsoon.

An EU funded project is focusing on assessing the effect of Himalayan glaciers retreat on water distribution in Northern India, as it may create droughts. It also studies the possible consequences on the famous Indian summer monsoon.

The urgency to study Himalayan glaciers came from a 2007 International Panel on Climate Change (IPCC) report—later proven not only alarmist, but downright wrong—claiming that they would have disappeared by 2035.

The Himalayan glacier research has resulted in a recommendation for a different type of crop management—involving a change in the amount of fertiliser used, growing different plants, or planting them closer together so agricultural water usage can be reduced by up to 30 per cent.

But giving scientifically sound advice and getting people to take it, are two completely different things, especially in India.

In the view of Anne van Urk, a hydraulic engineer who’s spent most of his career on the Indian subcontinent, such advice will not work.

“First, India is a deeply feudal society, so farmers will never change anything without asking permission to the landowner, or whoever they consider to be their superior,” he said.

“Second, the day to day problems of people in India are so enormous they can’t possibly think of crises that may or may not arise in 50 years.”

When it comes to water storage, the research clearly advises that a larger number of smaller storage basins would be more practical than a few very big ones.

Van Urk added: "While many small water storage basins are indeed a good idea, they are just not going to be constructed as long as people are more worried about what they’re going to eat tomorrow.”

The Worldwatch Institute study also says that policymakers must introduce a variety of measures to address global water scarcity.

One important initiative is to support small-scale farmers. Much of the public investment in agricultural water management has focused on large-scale irrigation systems.

Farmers can also use water more efficiently by taking a number of steps, including growing a diverse array of crops suited to local conditions and adopting irrigation systems like “drip” lines that deliver water directly to plants’ roots.

Climate change will affect global water resources at varying levels. Reductions in river runoff and aquifer recharge are expected in the Mediterranean basin and in the semiarid areas of the Americas, Australia, and southern Africa, affecting water availability in regions that are already water-stressed.

In Asia, the large areas of irrigated land that rely on snow-melt and high mountain glaciers for water will be affected by changes in runoff patterns, while highly populated deltas are at risk from a combination of reduced inflows, increased salinity, and rising sea levels. And rising temperatures will translate into increased crop water demand everywhere.

To combat the effects of climate change, efforts must be made to follow an integrated water resource management approach on a global scale. This involves water management that recognizes the holistic nature of the water cycle and the importance of managing trade-offs within it, that emphasizes the importance of effective institutions, and that is inherently adaptive.